The present invention relates to a liquid leakage inspecting device which inspects a barrel-like liquid container containing beer, for instance, and detects liquid leakage from the mouth of the container.
Conventionally, a container for beer is barrel-shaped and made of an aluminum plate or steel plate. The barrel-shaped container is strong, and has a relatively large capacity. The capacity of such a container is 7 litters, 10 litters, 15 litters, 20 litters, 25 litters, or 50 litters. The container is provided with a sealing stopper unit in its mouth portion to maintain the quality of the content liquid sealed in the container, and to prevent the content liquid from deteriorating and losing flavor.
The sealing stopper unit comprises: a mouth portion 1a formed on the upper surface or the lower surface of a container 1 containing liquid such as beer B; a bush a placed in the mouth portion 1a; a liquid raising cylindrical member c inserted into the bush a by the pushing force of first springs b; a gas valve d provided on the outer periphery of the upper surface of the liquid raising cylindrical member c so as to be engaged with the inner surface of the upper portion of the bush a; and a solution valve f which raises the content liquid by pressure air G supplied into the container 1 through the liquid raising cylindrical member c when the gas valve d is opened by the pushing force of second springs e, and which valve f discharges the content liquid out of the container 1.
In the production line of the beer B, defective products whose content liquid is leaking from the mouth portion 1a of the container 1 are detected and then discharged out of the main line of the production line. The container 1 is repeatedly used in view of resource conservation.
In the liquid leakage inspecting device, which judges whether the content liquid is leaking from the mouth portion 1a of the container 1, pure water w is injected into a concave portion g formed on the upper surface of the sealing stopper unit 4xe2x80x2 in the mouth portion 1a of the container 1, and a probe P is then put in the pure water w to measure its electric conductivity, thereby detecting liquid leakage.
In FIGS. 8 and 9, cylinders Sxe2x80x21 are disposed on both sides of a conveyer 2xe2x80x2 which transports the container 1 having the sealing stopper unit 4xe2x80x2 in the mouth portion 1a. The rods of the cylinders Sxe2x80x21 are provided with clamp units 12xe2x80x2 which can be opened and closed with respect to rotational axes 16xe2x80x2. The clamp units 12xe2x80x2 are connected to holding frames 15xe2x80x2 provided with rollers 14xe2x80x2, and holds the container 1 for liquid leakage inspection by a leakage inspecting unit 20xe2x80x2. In the next step to the clamp units 12xe2x80x2 on the conveyer 2xe2x80x2, cylinders Sxe2x80x22 provided on both sides of the conveyer 2xe2x80x2 are actuated to extend the rods toward the axis center O of the container 1. Stopper units 17xe2x80x2 having contact portions are attached to the edges of the respective rods of the cylinders Sxe2x80x22. In the next step to the stopper units 17xe2x80x2, a water supply unit 31xe2x80x2 which supplies the pure water w into the concave portion g formed in the upper portion of the sealing stopper unit 4xe2x80x2 is formed. In the next step to the water supply unit 31xe2x80x2, a probe P and a leakage inspecting unit 20xe2x80x2 are formed. The double-cylindrical probe P is inserted into the pure water w supplied into the concave portion g to measure the electric conductivity of the water, thereby judging whether the content liquid is leaking from the mouth portion 1a. The leakage inspecting unit 20xe2x80x2 is provided with a water supply unit 31xe2x80x3 which rotates in the vertical direction by 90 degrees in the ascending position of the probe P after the measurement, and which water supply unit 31xe2x80x3 supplies wash water to wash the probe P. In the next step to the leakage inspecting unit 20xe2x80x2, an air supply unit 43xe2x80x2 which blows dry air or hot air to the water in the concave portion g is provided. In the next step to the air supply unit 43xe2x80x2, a reject conveyer 45xe2x80x2 is provided. The reject conveyer 43xe2x80x2 transports the container 1 judged to be a defective product having leakage and discharged out of the main line of the production line by actuating a reject cylinder Sxe2x80x26.
Positioning units 21xe2x80x2 are formed in the locations of the water supply unit 31xe2x80x2, the leakage inspecting unit 20xe2x80x2, and the air supply unit 43xe2x80x2. Each of the positioning units 21xe2x80x2 stops and positions the container 1 being transported on the conveyer 2xe2x80x2. Cylinders Sxe2x80x23 and Sxe2x80x24 as driving power sources are provided on both sides of the conveyer 2xe2x80x2. The edge of each rod of the cylinders Sxe2x80x23 is provided with a grip unit 50xe2x80x2 having an arcuate inner surface 50xe2x80x2a corresponding to the outer peripheral surface 1b of the container 1. Each rod of the cylinders Sxe2x80x24 extends toward the axis center O of the container 1, and is provided with a contact portion 24xe2x80x2 (not shown) which can be in contact with the outer peripheral surface 1b of the container 1. The conveyer 2xe2x80x2 is a belt conveyer or a roller conveyer, for instance.
In a conventional liquid leakage inspecting unit shown in FIG. 8, pure water is injected into the concave portion g formed in the mouth portion g of the container 1 being transported on the conveyer in the pure water injecting position. When the container 1 being transported on the conveyer reaches the inspecting position, the probe P is inserted into the pure water in the concave portion g to measure the electric conductivity of the water. Here, the pure water injecting position is situated at a distance from the inspecting position. Because of this, the pure water injected into the concave portion g of the container in the pure water injection position is subjected to the vibration from the conveyer or the shock caused by the container 1 brought into contact with the guide members. As a result, the pure water flows out of the concave portion, hindering accurate measure of the electric conductivity.
There is another problem that the electric conductivity can be measured only when the beer B is leaking into the pure water from the gas valve d or the solution valve f of the sealing stopper unit 4xe2x80x2, because the probe P is inserted into the pure water w injected only into the concave portion g formed on the upper surface of the sealing stopper unit 4xe2x80x2.
In other words, leakage from the boundary between the mouth portion 1a and the bush a cannot be detected.
In the conventional liquid leakage inspecting device shown in FIGS. 8 and 9, the probe P is rotated in the vertical direction by 90 degrees in its ascending position after the leakage detection by the probe P inserted into the pure water w supplied into the concave portion g of the mouth portion 1a from the water supply unit 31xe2x80x2 of the leakage inspecting unit 20xe2x80x2. The water supply unit 31xe2x80x3 then supplies wash water to wash the probe P. After that, the air supply unit 43xe2x80x2 provided in the next step to the leakage inspecting unit 20xe2x80x2 blows dry air or hot air to dry the washed probe P.
As described above, washing the probe P requires a rotating operation of the probe P. Also, since the air supply position is situated at a distance from the water supply position, the drying of the probe P adds to the number of procedures, resulting in poor efficiency of the liquid leakage inspection on the conveyer 2xe2x80x2.
Furthermore, since the water supply unit 31xe2x80x3 supplies water only to the outer surface of the probe P, the inside of the double-cylindrical probe P cannot be sufficiently washed. As a result, dust and impurities remain in the probe P, thereby causing a problem that accurate leakage detection cannot be achieved with the repeatedly used probe P.
In the conventional liquid leakage inspecting device shown in FIG. 8, the container 1 being transported on the conveyer 2xe2x80x2 is sandwiched by the rollers 14xe2x80x2 in the clamp unit 12xe2x80x2 when the cylinders Sxe2x80x21 as the driving power sources on both sides of the conveyer 2xe2x80x2 are actuated. In the stopper unit 17xe2x80x2, the contact portions 24xe2x80x2 at the edges of the extended rods of the cylinders Sxe2x80x22 disposed on both sides of the conveyer 2xe2x80x2 are brought into contact with the sides and the front of the outer peripheral surface 1b, thereby stopping the transportation of the container 1. In the locations of the water supply unit 31xe2x80x2, the leakage inspecting unit 20xe2x80x2, and the air supply unit 43xe2x80x2, each of the cylinders Sxe2x80x23 and Sxe2x80x24 disposed on both sides of the conveyer 2xe2x80x2 is actuated so that the container 1 is sandwiched by the contact portion 24xe2x80x2 and the corresponding grip unit 50xe2x80x2 having the arcuate inner surface 50xe2x80x2a. 
The barrel-shaped container 1 made of an aluminum plate or a steel plate is forcibly pressed at both sides by the cylinders Sxe2x80x21 to Sxe2x80x24 disposed on both sides of the conveyer 2xe2x80x2, every time axis center matching, positioning, or transportation halting is performed on the conveyer 2xe2x80x2. As a result, the outer surface of the container 1 is often damaged or deformed. If repeatedly used over a long period of time, the container 1 is deformed during transportation or storing, resulting in irregularity in shape.
If the container 1 is deformed, the nozzle of the water supply unit 31xe2x80x2 is situated outside the concave portion g. In such a case, the pure water necessary for the inspection cannot be pooled sufficiently in the concave portion g. Also, the axis center Oxe2x80x2 of the probe P does not correspond to the axis center O of the container 1 and is situated outside the concave portion g. As a result, the probe P cannot be inserted properly into the concave portion g, but the probe P might be brought into contact with the inner surface of the concave portion g instead. This causes errors in the leakage inspection, and containers might be wrongly judged to be defective products even when there is no leakage. With the above problems, accurate leakage detection cannot be expected.
If the containers vary in size, it is necessary to change the grip units 50xe2x80x2 in accordance with the size of each container.
The present invention provides a liquid leakage inspecting device which eliminates the above problems with the conventional liquid leakage inspecting device, such as the poor accuracy in the detection due to the insufficient amount of pure water, and the inability to detect leakage from the boundary between the mouth portion of the container and the bush. In the liquid leakage inspecting device of the present invention, the pure water injecting position corresponds to the inspecting position on the conveyer, and the pure water necessary for the inspection is supplied in the inspecting position. The pure water is prevented from flowing out during the transportation of the container, so that the electric conductivity can be measured with high accuracy. Accordingly, the liquid leakage inspection can be efficiently conducted. Also, liquid leakage from the boundary between the inner surface of the mouth portion of the container and the outer surface of the bush can be automatically and quickly detected. Moreover, the structure of the device of the present invention is simple, and the number of components is small. Thus, compared with the prior art, the production procedures can be simplified, and the production costs can be reduced.
The present invention also provides a liquid leakage inspecting device which eliminates the problem with the drying and washing of the conventional probe, performs the washing and drying of the probe in a short time with little trouble, and efficiently conducts liquid leakage inspection with high accuracy.
The present invention further provides a liquid leakage inspecting device which eliminates the problems with the prior art, such as the inaccurate inspection due to damage or deformation of the container, and inability to comply with different sizes of the container. In the liquid leakage inspecting device of the present invention, the container being transported on the conveyer can be prevented from being damaged or deformed, so that the container can be repeatedly used over a long period of time. The axis matching of the probe can be easily and accurately in accordance with the shape and size of the container, and the container can be easily and accurately positioned and stopped at a desired inspecting spot. The pure water for the leakage inspection can be sufficiently supplied into the concave portion, and the container can be prevented from being wrongly judged to be a defective product. Thus, the device of the present invention can perform highly accurate liquid leakage inspection.
To eliminate the above problems, the present invention provides a leakage inspecting device which has a sealing stopper unit comprising: a bush attached to a mouth portion of a container containing liquid such as beer being transported on a conveyer; a liquid raising cylindrical member movably inserted into the bush in the vertical direction; a gas valve which can be opened and closed, is formed on the outer periphery of the upper surface of the liquid raising cylindrical member, and is engageable with the inner surface of the upper portion of the bush; and a solution valve which raises the content liquid through the liquid raising cylindrical member by supplying pressure air into the container when the gas valve is opened, and then discharges the content liquid out of the container, and which device measures the electric conductivity of water by inserting a probe into pure water supplied into a concave portion formed in the upper portion of the sealing stopper unit in the mouth portion of the container, thereby judging whether the content liquid is leaking. The leakage inspecting device comprises: a unit which places a positioning member on the mouth portion of the container being transported on the conveyer at an inspecting spot, with the axis center of the positioning member corresponding to the axis center of the mouth portion of the container; a unit which places an inner stand wall onto the upper surface of the mouth portion and also situates the inner stand wall on the outer periphery of the mouth portion, the inner stand wall being formed inside the positioning unit and having a larger diameter than a boundary surface between the mouth portion of the container and the bush attached to the mouth portion; a unit which inject the pure water into the inner stand wall and the concave portion formed in the mouth portion connected to the inner stand wall; and a unit which measures the electric conductivity of the water by inserting the probe into the pure water injected into the inner stand wall and the concave portion of the mouth portion, thereby judging whether the content liquid is leaking from the container.
In the leakage inspecting device of the present invention, the positioning unit can move up and down, and can cover the mouth portion of the container being transported on the conveyer. Also, an inclined guide portion which can forcibly move the container in the direction of the axis center thereof by touching the mouth portion is formed on the inner surface of the lower portion of the positioning unit.
The container and the probe can be moved up and down relatively with each other by driving power sources, and the probe is inserted into the mouth portion of the container.
The positioning unit is secured below an attachment plate in such a manner that the positioning unit can be placed onto the mouth portion, and the probe having a protruding edge is attached to the attachment plate.
The positioning unit may be disposed separately from an attachment plate in such a manner that the positioning unit can be placed onto the mouth portion, and the probe having a protruding edge is attached to the attachment plate.
The positioning unit is externally shaped like an up-side-down saucer or a bell, and a step portion which can be placed on the upper rim of the mouth portion of the container is formed on the lower surface of the inner stand wall. The step portion intersects the axis center. An inclined guide portion which broadens downward is formed under the step portion. The inclined guide portion matches the axis centers with each other by forcibly moving the mouth portion of the container in a horizontal direction intersecting the axis center when the positioning unit covers the mouth portion.
The leakage inspecting device of the present invention further comprises a water supply unit which supplies wash water to the probe and an air supply unit which blows dry air or hot air to the probe. The water supply unit and the air supply unit are situated in the ascending position of the probe in the inspecting position.
The probe has a water passing hole which communicates with the water supply unit and an air injection hole which communicates with the water supply unit. The water passing hole and the air injection hole are situated on the outer periphery of the probe.
In the leakage inspecting device of the present invention, a movable guide bar which adjusts the transportation width of the conveyer in accordance with the size of the container being transported is attached to one side of the conveyer. The axis center of the probe of the leakage inspecting unit corresponds to the center line extending in the longitudinal direction of the transportation width.
The conveyer is provided with a stopper unit comprising a guide bar movable in a direction intersecting a transportation direction of the container by a driving force of a cylinder as a driving power source on one side of the conveyer, and a rod which can be moved toward the axis center of the container by a driving force of another cylinder, and can be in contact with an outer peripheral surface of the container, and extension lengths of rods of the two cylinders are controlled in accordance with the size of the container being transported, so that the axis center of the probe is matched with the center line of the transportation width of the conveyer.